Presently, a variety of so-called fiber-reinforced engineering polymers are used in a wide range of applications and industries. For example, in the automotive industry they are used as truck lids, van hoods, door panels, bumpers and the like. These plastics can contain as much as 50% by weight of fibers of varying character, including fiberglass, and the fibers can be categorized as short length, long length, and continuous. Many of these fiber reinforced resin composites are of the long fiber variety ranging from 0.2 to 6 mm in length, compared to a range of 0.1 to 0.5 mm in a short fiber composite. Typical synthetic plastics which are utilized are polycarbonates, polyamides, epoxys, and polyurethanes. Such composites, particularly of the long fiber variety, have greatly increased flexural strength and impact strength.
When attempting to drill holes in such materials, which, for example, may have a thickness of 1/8 to 1/4 of an inch, with conventional drills, a number of serious problems are encountered. For example, a considerable vibration or chattering occurs which generates a loud noise and further results in holes which are not within size or quality tolerances. Further, the standard tools tend to break out the back side of the plastic, leaving corners which are not sharp and fiber fuzz which extends into the openings drilled, from the marginal walls thereof.